The focus of this Mentored Clinical Scientist Development Award (MCSDA) is to enable David Oslin, MD to acquire academic and research expertise for the treatment of late life mental disorders including major depression and comorbid alcoholism. Dr. Oslin is currently an Assistant Professor of Psychiatry at the University of Pennsylvania with appointments in the Section of Geriatric Psychiatry and the Center for Studies on Addiction. His career goals include: 1) gaining expertise in study design and methodology for intervention research, 2) establishing independent research projects on the treatment of comorbid mental health disorders, 3) enhancing his clinical expertise in the prevention, recognition and treatment of late life mental illness, and 4) being a resource for the university community on the research and clinical care of older adults, especially those with comorbid mental health problems. The proposal for this application includes both formal and informal instruction in research design and methodology as well as an intervention development project that will have both educational and scientific significance. The research plan for this award includes an intervention development study for older adults with primary major depression complicated by alcohol dependence. The aim of the project is to evaluate the tolerability and efficacy of naltrexone compared to placebo as a treatment for alcoholism in combination with sertraline as a treatment for primary major depression. Focusing on older adults enhances the goal of examining primary depression and comorbid alcoholism as the literature suggests that alcoholism is more often secondary to major depression in older adults compared to younger adults. This research plan is seen as a step toward the design of future studies of comorbidity in late life major depression. A growing awareness of a strong association between depression and alcohol abuse/dependence, the need for safe and effective treatments for comorbidity, and ever-present problem of gaining patient compliance with treatment regimens all appear to be fertile ground for study in an older population. The MCSDA would provide an important vehicle via course work and mentoring to enable Dr. Oslin to advance his knowledge and experience in these areas, which in turn, may advance the field of psychiatry's understanding of these complex issues. Dr. Oslin's training in geriatric psychiatry and addictions also makes him a good candidate to conduct the proposed intervention study. Finally, proposed plans for this MCSDA are well coordinated with the research activities of the Section of Geriatric Psychiatry and the Center for Studies on Addiction.